1. Field of the Invention
The present invention relates to a user interface fabrication for a PC system, and more particularly to a user interface device for a PC system, which is capable of converting user interface data outputted from external input devices such as a remote controller to data which may be recognized by a PC system.
2. Discussion of the Background
FIG. 1 illustrates a conventional user interface in a PC system for which a keyboard and a mouse are used as external input devices.
As shown therein, a keyboard 40 and a mouse 50 which are connected with a keyboard controller 30 through clock lines KCLK, MCLK and data lines KDATA, MDATA respectively supply 11 bit serial data, that is a start bit, 8 data bits, a parity bit and a stop bit, to the keyboard controller 30, and the keyboard controller 30 outputs a clock signal to the key board 40 and the mouse 50, respectively. The keyboard controller 30 supplies interrupt signals IRQ1,IRQ12 to a system 60 and transmits a data format which can be recognized by the system 60 to the system 60 through an 8 bit data bus XD0-XD7. The system 60 performs an application program in accordance with the input data, for thereby using the data when necessary.
FIG. 2 illustrates another conventional user interface to which a remote controller 10 is additionally supplied to the construction of the user interface shown in FIG. 1.
As shown therein, there are provided a remote controller 10 for transmitting a radio signal in accordance with a key input generated by a user and a receiver 20 for supplying predetermined code data corresponding to the radio signal to the keyboard controller 30. The operation of the keyboard 40 and the mouse 50 is same as the above-described operation. An operation of the remote controller 10 will be described as follows.
When the user presses a predetermined key of the remote controller 10, the remote controller 10 converts an 1 byte key code to a radio signal, such as an infrared, of a predetermined format, for example a 2 byte signal comprised of 1 byte ID and 1 byte data, and transmits the converted signal through a data line RDATA to the receiver 20 which generates serial key code data corresponding to the signal received from the remote controller 10 and supplies the generated key code data to the keyboard controller 30 in accordance with the clock signal from the keyboard controller 30.
The keyboard controller 30 applies a system management interrupt (SMI) to the system 60. Here, the interrupt SEMI for system power management is applied at least in PC 386, and the system 60 which has received the interrupt SMI prepares for support of a BIOS code by which a routine of an internal program jumps to a corresponding address, and thus it becomes possible for a system BIOS to be interfaced with the remote controller 10.
After the system 60 has been ready, the keyboard controller 30 supplies the inputted key code data through the data bus XD0-XD7 to the system 60 which stores the inputted code in a predetermined memory such as NVRAM, for thus the code may be applied to other application programs.
On the other hand, in the thusly operated system, the function of the external input device may be changed. Specifically, additional functions may be supplied to the remote controller for the convenience of the user, or a separate input device such as a scanning logic may be added thereto.
When the functions of the remote controller are changed, the corresponding codes are also changed. However, since the keyboard controller converts input data and unconditionally transmits the converted data to the system, the fixed functions are not able to process the changed codes. Accordingly, when changing the function of the remote controller or adding a separate external device, a receiver and a keyboard controller which are newly designed according to the changed external device should be supplied instead of the currently used receiver and keyboard controller. In addition, the BIOS program in the system should be modified in accordance with the external device.
The changing of the system BIOS program may not be problematic. However. the change of the keyboard controller is difficult because a new hardware must be provided therefor. In other words, the keyboard controller in the system should be changed although there is needed simple modification of the external input device, thereby degrading the compatibility and costing a great deal due to the change of the hardware.